Scooter lied

Why on earth did Scooter Libby tell lies to the FBI? Well, yes, to protect the Vice President and so forth and so on. But also, because he had good reason to fear that if he told the truth, he might go to prison. There is a law against "outing" a covert CIA agent. That law might or might not have applied in this case. Prosecutor Patrick Fitzgerald ultimately decided he couldn't make the charge stick, but Libby didn't know that when the FBI came calling. He gambled that lying was safer, and he lost.